Hello guys.

Not sure if to post this here or in the microtech section but it seems to be a car issue and not the ecu so I'm posting it here. My tach was working fine and out of the blue it started bouncing and cutting off. Now it will not do anything. The output from the ecu is working and I replaced the tach from another cluster which was working before. Still no luck. I've been reading all day and haven't found anything helpful. Obviously it's not the trailing coil because with the microtech you get the signal from the ECU not the coil. The yellow cable located by the coils is properly connected to the ecu tach output. I also checked the fuses and they're not burned. I saw on a post that there is certain ground thy could be faulty but I have no idea of which one we are talking about!! The car is a 1989 T2 and I'm using a microtech LT-10C. Thanks in advance.

 

Bump

 

Get a new trailing coil and see what happens......

 

Just to elaborate on the above post, The tach signal comes from the trailing coil. If the trailing coil doesn't fire, you have no tach.

Now you could in the mean time run a jumper and get tach from the leading coil, but that will not fix the fact the trailing coil is not firing, it will only fix your tachometer.

 

Ok. If it was to be a stock car I would definitely agree with you. However this car uses a microtech ecu. It collects rpm's from the ecu not from the trailing coils. All 4 coils are firing as they should be. I am getting the rpm signal from the ecu. It's an issue with the dash or wiring itself not with the coils. Thanks for the input anyways

 

Bump

 

check the meter fuse inside the cabin.

 

Already did. It's good. Still no tach ��

 

Your driving too slow
In all reality swap your coil with another. Tachs usually don't die.

 

plus even with a microtech if you didn't rewire the tach then it is still running through the trailing coil. honestly mine still is because i never felt the need to rewire it. so there is that.

 

Yes the tachometer was rewired. All coils are fine

 

Do you have a multimeter? Can you check the output frequency of the microtec tach signal by just grounding it through the multi meter? (should see +5V pulse @ some frequency right?)

I don't know much about the microtec ECU but a PWM signal is a PWM signal no matter what. It's looking for so many pulses in a given instance.

If that checks out, check continuity and resistance from the ecu to the tach, probably have a broken wire somewhere in the loom.

If you can pin the back of the connecter while it's connected to the ECU that would be helpful too to see if the terminal has gone bad.

Andy

 

Why not just connect the tach to the trailing coil like it was originally and be done with it?

And if that doesn't work replace your tach.

 

I had this same problem and here is what I did and ever since I did this I have no problems. Take the tach guts out of the gauge cluster and clean around the screws that hold the guts in the cluster. They are ground screws and often get corrosion on them. Just a little corrosion can make it tweak out. I went through all the stuff everyone else on hear is talking about and this is what finally worked.

 

Ok. Thanks I'll get to working and keep you guys posted